Comparing Metro Phoenix
Sulphur Dioxide
Description: Sulphur Dioxide (SO2) is one of the criteria air pollutants identified by the EPA as being critical to assessing the environmental health of a place. Primary sources of SO2 are coal and oil combustion and activities from mining (smelters).
Rationale: SO2 is the primary component of acid rain. It also contributes to decreased visibility throughout the US, particularly in national parks. Human health is impacted from SO2 by aggravating breathing and pre-existing cardiovascular conditions. Annual mean concentration levels are identified in the graphs. The National Standard for this criteria pollutant is 0.03 parts per million (ppm). Of the comparator cities, only Phoenix, Atlanta, Denver, Salt Lake City, and San Diego were reported consistently throughout the time period. Reporting began in the remaining cities more recently in Austin (2003), Raleigh (2002), and Portland (2005) and ended in Seattle in 2005. While Phoenix is in attainment for SO2, nearby mining communities are in nonattainment. The Towns of San Manuel and Hayden, both located east of Phoenix in Pinal County report high concentrations of SO2 as a result of the copper smelting process. The only city located within a nonattainment area is Salt Lake City and this is the result of mining activities within the surrounding county.
Source: Decision Center for a Desert City (DCDC) using records from the U.S. Environmental Protection Agency's Monitor Trends Report - Criteria Air Pollutants.
